A problem almost universally encountered in the design of electronic devices is the harmful effect of electronic noise on the operation of such devices. One technique which has been found useful in reducing such harmful effect is the winding or twisting together of pairs or groups of insulated metal conductor wires whenever such wires pass from one part of the device to another. Such winding not only reduces the amount of electromagnetic noise radiated by wires carrying varying currents, but also reduces the amount to stray noise picked up by signal wires. In the past, the winding or twisting together of insulated conductor wire has mainly been accomplished manually, a process wich drastically limits the use of wound or twisted wire as a standard production technique, and which further produces a wound cable subject to unwinding.
The problem of machine winding a number of individual strands of material together into one composite strand or cable has been approached in many different arts. In the manufacture of rope and related materials, for example, the individual strands are twisted before being wound together, such twisting providing the force to hold the strands together in the finished rope. Methods of making glass fiber cable by coating the individual fibers with adhesive have also been developed. See for example U.S. Pat. No. 3,662,533. Such prior techniques, however, have little applicability to the winding of metal strands coated with thermoplastic insulating material. Twisting individual strands of such wire prior to winding would be impractical and ineffective. The use of adhesives, while possible, is better suited to applications in which the individual strands are thinner and more flexible than thermoplastic coated metal wire. All known winding techniques, if applied to insulated metal wire, would produce a cable with a tendency to curl, since the cable would retain a memory of the twisting of the individual wires. Finally, the large mass of spools of metal wire makes it quite difficult to design a winding machine for such wire capable of being operated at production speed without instability.